[BUG] npm_execpath is set to the path of npx instead of npm #6662

Is there an existing issue for this?

• I have searched the existing issues

This issue exists in the latest npm version

• I am using the latest npm

Current Behavior

The env npm_execpath can be path of npx instead of npm if the user runs a command with npx, e.g. npx node -e "console.log(process.env.npm_execpath)", the output will be /path/to/npm/9.8.1/bin/npx-cli.js

I did not find the official definition for npm_execpath, but I assume it should only be the path of npm based its name, not the path of npx.

Some popular libraries, e.g npm-run-all, using npm_execpath and assuming it's the package manager path and add run arg to it, so if you run npx npm-run-all test, it is the same as npx run test which will install a package called run and throw errors.

Yarn also suggests use $npm_execpath run <name> which can cause the same problem: https://yarnpkg.com/advanced/rulebook#published-packages-should-avoid-using-npm-run-in-their-scripts

Expected Behavior

npm_execpath should always be set as the path of npm.

Steps To Reproduce

Run npx node -e "console.log(process.env.npm_execpath)"

The output will be /path/to/npm/9.8.1/bin/npx-cli.js

Environment

• npm: 9.8.1
• Node.js: 20.4.0
• OS Name: MacOS
• System Model Name: Macbook Pro
• npm config:

n/a